Green groups hailed the new agreement between China and the U.S. to slash emissions of some potent greenhouse gases, but tough international negotiations lie ahead if the deal is to take effect.

The White House and the green community — which has been seeking action by President Barack Obama to fulfill his promises to more aggressively combat climate change — heralded a deal he cut over the weekend with Chinese President Xi Jinping to cut hydrofluorocarbon pollution.

The environmentalists hope the deal — which would fall under the Montreal Protocol, a treaty put into effect in 1989 to repair the ozone layer — can bring some political momentum for a far more expansive United Nations deal to reduce carbon dioxide.

The more immediate impact of the agreement with China is to increase support for an amendment proposed by the U.S., Canada and Mexico to reduce global hydrofluorocarbon emissions ahead of the 25th meeting of Montreal Protocol countries this October. Before this weekend’s agreement, China had sided with India and Brazil as the three major opponents to such a global deal.

“If you can get those three on, you can get this done,” said Andrew Light, a senior fellow at the Center for American Progress.

Secretary of State John Kerry will travel to India later this month in his first trip to the country since he took over the department, and the topic could arise on that visit.

Hydrofluorocarbons, which are used in appliances like refrigerators and air conditioners, have a much shorter lifespan in the atmosphere than carbon dioxide but still contribute to climate change.

The proposed amendment would phase down the production and consumption of the gases in all countries and require reporting on emission levels. It includes a financial assistance plan for countries and does not alter the reporting and accounting provisions of hydrofluorocarbons emissions under the U.N. Framework Convention on Climate Change and the Kyoto Protocol.

Crucial to getting a broader deal ratified will be setting the timeline for developed nations to act and establishing a grace period before developing countries would need to phase out their hydrofluorocarbons emissions.

“There is going to be a hard-fought battle to negotiate the terms of the amendment,” said Durwood Zaelke, president and founder of the Institute for Governance and Sustainable Development.

The weekend deal with China comes after 112 parties of the Montreal Protocol had already backed the idea of scaling down global hydrofluorocarbons emissions. “And the 113th party happens to be the single biggest producer. So it’s a huge breakthrough,” Zaelke said.

The Senate must ratify any agreement reached among the Montreal Protocol countries — a potentially daunting task, given the political paralysis on Capitol Hill.

But U.S. companies like Honeywell and DuPont that have been leading producers of alternatives to the gases are expected to lobby hard for any deal to be approved.

“We don’t think it’s going to be as big an obstacle as you might think because there’s no big opposition in the U.S. industry to do this,” Light said. It is also below the radar compared with the battles over carbon dioxide emissions. “So I don’t see a big fight,” Light said.

And unlike the unanimous opposition to ratifying the 1997 Kyoto Protocol, the Senate has historically been friendlier to the Montreal Protocol, and last approved an amendment to that treaty in 2000.

Even if there are hiccups to reaching a broader deal, the U.S. can still take action, as it has in the case of land mines, even though the Obama administration has refused to sign an international ban.

“But I don’t think that it will come to that,” Light said.

And regardless of a global deal, any action by the U.S. and China would steer markets away from hydrofluorocarbons.

That — along with efforts to reduce other short-lived greenhouse gases such as methane and black carbon — could help temporarily slow rising global temperatures, creating a tangible result and sparking U.N. discussions on reducing fossil fuels and carbon emissions.

“This is the first ever big coordinated action by the two largest emitters [and] potentially really a historic turning point,” said Paul Bledsoe, a senior fellow at the German Marshall Fund and former Clinton White House aide. “It develops an attitude that we can actually solve this problem. And that’s all the difference in the world,” he added.

“As a political matter, developing effective strategies that show results is the key to motivating people to get involved in advocacy and policy action. Up until now it seemed like sort of a hopeless battle,” thanks to struggling U.N. talks, he said.

“It shows that the U.S. and China can cooperate on climate change, and if we follow through on the success of the Montreal Protocol, it’s going to give us a great sense of encouragement and optimism” that a global climate deal could be reached when U.N. delegates meet in Paris in 2015, Zaelke said.

“I think the world is now seeing it’s better to do climate in multiple venues,” he said.

National Security Adviser Tom Donilon told reporters this weekend that the hydrofluorocarbons deal with China is “the sort of practical cooperation we’re working on to see more of in the climate change area and in other areas of our relationship.”

The deal between the U.S. and China comes as the International Energy Agency released data Monday, indicating that global energy-related carbon dioxide emissions rose 1.4 percent last year to a record high of 31.6 billion tons. That increase occurred even as the U.S. posted its lowest emissions since the mid-1990s.

In its annual World Energy Outlook report, IEA said China, the top carbon polluter, had the largest emissions growth last year, up 300 million tons, or 3.8 percent, from 2011. Still, the increase was among the lowest seen in a decade as China continues to invest in renewable energy and energy efficiency.

U.S. emissions dropped 200 million tons, or 3.8 percent, in part due to a switch from coal to gas for power generation, while Europe’s emissions declined by 50 million tons, or 1.4 percent, the IEA said.

The agency said the energy sector accounts for about two-thirds of global emissions of CO2 and other greenhouse gases.

The IEA said developing countries now account for 60 percent of global emissions from energy, up from 45 percent in 2000.

On Monday, the IEA issued a four-part plan to reduce greenhouse gas emissions from the energy sector and stay on track to limit the increase in global temperatures to 2 degrees Celsius.

The plan targets energy efficiency in buildings, industry and transportation, which IEA says would account for nearly half of the emissions reduction in 2020. It also calls for limits on construction and use of coal-fired power plants while increasing the share of natural gas and renewables in the power sector. It calls for cutting in half expected methane releases from the upstream oil and gas industry in 2020 and a partial phase-out of fossil fuel subsidies.